Waves

Overview

In the Waves Unit, students will be introduced to several new concepts involving the audible (hearing) and visible (seeing) world around them. Students will learn about general characteristics of waves as well as where waves are found in nature and used by humans.

Waves Choice Work

• Introduction to Choice Work
• Assignment Sheet and Calendar
• Waves in Your Life - Blog
• Worksheets
• Waves Paragraph - BCR
• Explore Choices - experiments
• Online Resources - information from the text about waves
• Other Web Resources

Introduction to Choice Work

One of the aspects of Middle School growth that I feel is important is increased responsibility. Choice Work helps students take ownership of their learning.

During the Waves Choice Work project, students will be presented with different activities that will help them with their understanding of Waves. Many of the activities are required, while some of the activities are choices. Each choice assignment has a point value that can be earned for completing it successfully. At the end of the project, the points will be added up for a final grade.

Grade Scale:

A = 86 - 100 pts.

B = 71 - 85 pts.

Assignment Sheet and Calendar

Each student will receive two documents to help them get organized:

• Waves Choice Work Format - lists all of the assignments and explains how to do them
• Waves Choice Work Calendar - a detailed time-line for completing the work

Worksheets

There are worksheets that go along with this project. Some are required, some are choices.

Required:

Wave Properties.pdf

Choice:

What Are Waves - Online Worksheet

Science Explorer Choice Work.pdf

Waves Paragraph (10 pts)

Visit this site and scroll down to Electromagnetic versus Mechanical Waves to learn about the differences between electromagnetic and mechanical waves.

Use the information from the website to respond to the following BCR (brief constructed response.)

There are two types of waves; mechanical and electromagnetic. Describe each, giving at least two details for each. In your response, be sure to

• name each type of wave

• describe each type by giving at least two details for each type of wave

• give an example for each type of wave

Click here to answer the question online.

Explore Choices

• Complete at least one of the following Explore Choice Experiments. You may work with a partner but you must turn in your own work.
• Copy the Question and write your hypothesis for each experiment.

How Can You Change a Wave?

Question

To what extent does the amount of energy you put into a wave affect the size of a wave?

Hypothesis

I think... because....

Materials__

• 1 rope or spring (a slinky would work)
• 2 partners
  • two to move the rope or spring
  • one to read directions

Procedures

1. Read All Procedures!
2. Copy the Question and write down your hypothesis.
3. Lay the spring on a smooth floor. Securely hold one end. Have a partner hold the other end .
4. Have one partner move the end of the spring left and right about once per second to make a series of waves travel down the spring. The other partner should hold their end of the spring still. Observe the waves as they travel toward your partner. Draw a labeled diagram of what you see.
5. Now move the end of the spring more often - about two times per second. Draw a new, labeled diagram to show any differences.
6. Switch roles with your partner and repeat steps 2 and 3.

Conclusion

Answer the following questions about the experiment.

1. What are the results of your experiment? (does the amount of energy you put into a wave affect the size of a wave?) Use details from the experiment to support your claim.
2. Was your hypothesis correct?
3. Was your data Qualitative or Quantitative? (click the link for a description of each) Explain what data shows this.
4. What were the variables in this experiment? (click here for a review of some terms)

• what is the Independent variable?
• what is the Dependent variable?

Hanger Experiment

Question

To what extent does the type of medium affect how well a wave travels?

Hypothesis

I think...because...

Materials

• metal coat hanger
• 2 pc yarn (50 cm)
• partner
• quiet room

Procedures

1. Read All Procedures!
2. Copy the Question and write your hypothesis.
3. Tie the end of each piece of yarn to the loop part of the coat hanger.
4. Wrap the yarn around each index finger.
5. Hang coat hanger down and have your partner tap the hanger with a pen or pencil. Record your observations.
   • What did you see?
   • What did you hear?
   • What did you feel?
6. Repeat steps 1-3 with your fingers in your ears. (make sure you are leaning over a little and that the hanger is hanging freely and not touching you) Record your observations.

Conclusion

Answer the following questions about the experiment.

1. What are the results of your experiment? (what is a better conductor of sound?) Was your hypothesis correct?
2. Was your data Qualitative or Quantitative? (click the link for a description of each) Explain what data shows this.
3. What were the variables in this experiment? (click here for a review of some terms)

• what is the Dependent variable?
• what are the Controlled variables? (there are more than one)

Online Resources

The science text has online resources to help you with this unit at home.

• Properties of a Wave
• Wave Interference
• Waves Self Assessment
• Crossword Puzzle Maker

Other Web Resources

• Types of Poetry - description of different types of poetry

Color and Vision SimulationThe following simulation will help you make a rainbow by combining red, blue, and green light. It will also help you see what happens when you use a filter on different colored light.Start by downloading this worksheet:

PhET Simulation - Color Vision.doc

Go to this site and choose Run Now to begin the simulation. Follow the directions on the worksheet.

Refraction Experiments

Magic Pencil

Materials:

• Pencil

• Water

• Clear Glass or Jar

Procedures:

1. Fill the glass or jar half way with water.

2. Place the pencil in the water.

3. Look at the pencil from the top.

4. Look at the pencil from the bottom

5. Look at the pencil from the sides.

Conclusion

1. What happens when you look at the pencil through the top of the glass?
2. What happens when you look at the pencil through the side of the glass?
3. Draw a diagram of what you saw.

Floating Penny

Materials:

• Penny

• Water

• Clear glass or jar

• cup to pour with

Procedures:

1. Place the penny in the bottom of the glass.

2. Walk around and observe the penny from several angles – top, side, etc.

3. Have one person slowly pour water into the glass while others observe from different angles.

4. Repeat step three with a different person pouring and others observing from different angles.

Conclusion

1. What do you see?
2. How does the angle you observe from affect what you see?
3. Draw a diagram of what you saw.

Explanation:

• What you observed in both experiments happens because light travels slower through different materials (such as water) than through air. As the light enters the glass of water it slows down and as it leaves the glass it speeds up again. If the light enters at an angle the pencil looks as though it is bent and the penny appears to float or disappear!

Magic Pencil

Materials:

• Pencil

• Water

• Clear Glass or Jar

Procedures:

1. Fill the glass or jar half way with water.

2. Place the pencil in the water.

3. Look at the pencil from the top.

4. Look at the pencil from the bottom

5. Look at the pencil from the sides.

Conclusion

1. What happens when you look at the pencil through the top of the glass?
2. What happens when you look at the pencil through the side of the glass?
3. Draw a diagram of what you saw.

Floating Penny

Materials:

• Penny

• Water

• Clear glass or jar

• cup to pour with

Procedures:

1. Place the penny in the bottom of the glass.

2. Walk around and observe the penny from several angles – top, side, etc.

3. Have one person slowly pour water into the glass while others observe from different angles.

4. Repeat step three with a different person pouring and others observing from different angles.

Conclusion

1. What do you see?
2. How does the angle you observe from affect what you see?
3. Draw a diagram of what you saw.

Explanation:

• What you observed in both experiments happens because light travels slower through different materials (such as water) than through air. As the light enters the glass of water it slows down and as it leaves the glass it speeds up again. If the light enters at an angle the pencil looks as though it is bent and the penny appears to float or disappear!

How you See Color

Reflection Experiment

Two Types of Reflection

Materials

• 1 piece of aluminum foil (15cm x 15cm)

• 1 flashlight

Procedures

1. Place the piece of aluminum foil on a flat table with the shiniest side facing up. Be careful to keep it smooth and unwrinkled!

2. Shine the flashlight at an angle on the surface of the foil and look up at the ceiling. What happens to the beam of light after it hits the surface?

3. Crumple the foil and then flatten it out.

4. Shine the flashlight at the surface of the crumpled foil and look back at the ceiling again. What happens to the beam of light now?

Conclusion

1. When light reflects with a perfect image of the original we say that it has a regular reflection. Which aluminum foil piece had a regular reflection?

2. If light is scattered when it hits a surface we say it has a diffuse reflection. Which aluminum foil piece had a diffuse reflection?

3. What are some examples of regular and diffuse reflections in your life?

Individually, answer the following questions

• Does a water wave have all of the same properties as a rope wave?
• What are some differences between a rope wave and a water wave?
• Can you change a water wave the same way you can change a rope wave?

Complete the following investigation with the other members of your group.

Materials

• shallow tray that can hold water
• pencil

Procedures

1. Pour water into your tray until it just reaches the top edge without spilling over.
2. Tap the surface of the water at one end of the tray once every second with the end of a pencil.
3. Draw a diagram in your notebook to show the effects of this tapping on the surface of the water (remember that a diagram is a labeled drawing.)
4. Now, tap the surface of the water twice every second. Try to tap with the same amount of energy. Draw a diagram to show the effects. Be sure to note any differences that may have occurred.
5. Recall the names of the parts of a transverse wave:
   • rest position
   • crest
   • trough
   • wavelength
   • amplitude
6. Did you see these parts in the water wave?
7. What properties of the water wave did you change when you tapped the water more times? Describe the change. Be sure to use the above vocabulary.
8. What would happen to the wave if you tapped the water three times per second? Why do you think this?
9. How would you change the amplitude of your water wave? Explain what you would do and why you think it would work. Try it!
10. Draw a diagram to represent your new wave.